readahead: drop pointless index from force_page_cache_ra()

Current index to readahead is tracked in readahead_control and properly
updated by page_cache_ra_unbounded() (read_pages() in fact).  So there's
no need to track the index separately in force_page_cache_ra().

Link: https://lkml.kernel.org/r/20240625101909.12234-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/readahead.c b/mm/readahead.c
index 1c58e0463be197ea77093176f3fd22e777739787..455edafebb07933190d6910b9d7c4cea6341b81d 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -313,7 +313,7 @@ void force_page_cache_ra(struct readahead_control *ractl,
        struct address_space *mapping = ractl->mapping;
        struct file_ra_state *ra = ractl->ra;
        struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
-       unsigned long max_pages, index;
+       unsigned long max_pages;
 
        if (unlikely(!mapping->a_ops->read_folio && !mapping->a_ops->readahead))
                return;
@@ -322,7 +322,6 @@ void force_page_cache_ra(struct readahead_control *ractl,
         * If the request exceeds the readahead window, allow the read to
         * be up to the optimal hardware IO size
         */
-       index = readahead_index(ractl);
        max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages);
        nr_to_read = min_t(unsigned long, nr_to_read, max_pages);
        while (nr_to_read) {
@@ -330,10 +329,8 @@ void force_page_cache_ra(struct readahead_control *ractl,
 
                if (this_chunk > nr_to_read)
                        this_chunk = nr_to_read;
-               ractl->_index = index;
                do_page_cache_ra(ractl, this_chunk, 0);
 
-               index += this_chunk;
                nr_to_read -= this_chunk;
        }
 }